[FIXED] Error psycopg2.OperationalError: fe_sendauth: no password supplied even after postgres authorized connection

Issue

My python script is raising an 'psycopg2.OperationalError: fe_sendauth: no password supplied' error, even though the Postgre server is authorizing the connect.

I am using Python 3.5, psycopg2, Postgre 9.5 and the password is stored in a .pgpass file. The script is part of a restful flask application, using flask-restful. The script is running on the same host as the Postgre server.

I am calling the connect function as follows:

conn_admin = psycopg2.connect("dbname=database user=username")

When I execute the script I get the following stack trace:

   File "/var/www/flask/content_provider.py", line 84, in get_report
     conn_admin = psycopg2.connect("dbname=database user=username")
   File "/usr/local/lib/python3.5/dist-packages/psycopg2/__init__.py", line 130, in connect
     conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
psycopg2.OperationalError: fe_sendauth: no password supplied

However when I look at the Postgre server log I see the following (I enabled the logger to also show all connection requests):

2019-01-04 18:28:35 SAST [17736-2] username@database LOG:  connection authorized: user=username database=database 

This code is running fine on my development PC, however when I put it onto the Unbuntu server, I start getting this problem.

To try and find the issue, I have hard-coded the password into the connection string, but I still get the same error.

If I execute the above line directly into my Python terminal on the host, it works fine, with and without the password in the connection string.

EDIT: One thing I did notice is that on my desktop I use Python 3.6.2, while on the server I use Python 3.5.2.

Solution

Try adding the host:

conn_admin = psycopg2.connect("dbname=database user=username host=localhost")

Answered By - Bruno Carballo